The subject matter disclosed herein relates to turbines, and more particularly to a mechanism for damping vibrations and sealing the spaces between adjacent blade assemblies of circumferentially spaced blade assemblies in a turbine.
Turbine engines typically have a plurality of circumferentially spaced blade assemblies mounted on a rotor for rotation therewith about the rotor axis. These blade assemblies exist in a number of different shapes and configurations, but generally have an innermost dovetail portion an intermediate portion with a platform portion having shank portions depending therefrom and an outermost airfoil portion, with the dovetail portion being slidably received in a complimentarily configured recess provided in the rotor. The shank portions separate the dovetail and platform portions, while also defining a pocket for cooling fluid. It has become common practice to introduce cooling fluid, usually air, between adjacent blade assemblies to enhance metallurgical limitation on blade assemblies operating under high inlet temperatures. The platform portions separate the shank and airfoil portions. The airfoil portion typically depends radially into the passageway to interact with the working fluid. At the same time, however, these airfoil portions are subject to harmonic stimuli. The source and nature of such blade vibrations are difficult to identify and eliminate. There is a general need and desire to damp such vibrations. So it has become common practice for damper assemblies to effectively decrease the harmonic stimuli of a turbine engine.
Although these known damper assemblies may be largely adequate, the cooling fluid leaks across the damper assemblies into the working fluid, decreasing the efficiency of the turbine engine. So it has become particularly beneficial to use a damper assembly that can improve sealing about adjacent blade assemblies.